The invention relates to a fountain pen with a tubular barrel, an ink guide mounted in the barrel and having a nib attached to the front end thereof, and an ink reservoir in the form of an ink cartridge fitted onto the rear end of the ink guide. The ink guide is displaceable (substantially linearly movable) between a writing position in which its front end area projects out of the front end of the barrel, and a storage position in which the front end area of the ink guide, and the nib attached to it, are retracted into the barrel. In known fountain pens of this kind (such as in French Patent 1 539 276 and U.S. Pat. No. 3,203,403), the fitting of a new ink cartridge and the removal of an empty cartridge, are carried out in such a way that a rear part of the tubular barrel is removed from the front part of the tubular barrel so that the ink cartridge becomes accessible and can be gripped and pulled out of the barrel, and a new ink cartridge fitted onto the rear end area of the ink guide.
The invention provides a fountain pen with retractable ink guide and nib that allows the ink cartridge to be replaced easily, more easily than in the prior art. This is accomplished by providing a pen wherein the ink guide can be moved from the storage position into a replacement position in which the rear end of the ink cartridge fitted in or on the ink guide projects out of the rear end of the barrel, and can be readily grasped for removal.
The fountain pen according to the invention is thus, as is conventional, fitted with a replaceable ink cartridge which forms the ink reservoir and is positioned on the rear end of the ink guide so that, in a conventional manner, ink from it can enter through a central opening of the ink guide into the latter and pass forward to the nib. However, to allow the ink cartridge to be easily replaced, without disassembling the barrel, the ink guide is movable into a replacement position, rearward of the storage position, in which the fitted ink cartridge is located wholly inside the barrel. In the replacement position, the rear end of the ink cartridge projects out of the rear end of the barrel so that the user can grasp the ink cartridge and pull it off of the rear end of the ink guide in order to replace it with a new full ink cartridge.
In a preferred embodiment of the invention, a closure cap is pivotally mounted near or at the rear end of the barrel so that the barrel rear open end is covered by the closure cap in normal operation. When the closure cap is moved into its opening position the ink guide may be moved from the storage position into the replacement position in order that the rear end of the barrel is open to receive the ink cartridge.
To facilitate the displacement movement of the ink guide between the writing position, storage position, and replacement position, a positioning sleeve can be provided that is rotatable with respect to, but axially non-displaceable in, the barrel. The sleeve has a thread-like track engageable by at least one catch, non-displaceably connected to the ink guide. In this way, when the positioning sleeve is rotated, a helical displacement (substantially linear) movement of the catch is effected relative to the positioning sleeve and thus a corresponding axial displacement movement of the ink guide. A particularly uniform displacement (substantially linear) movement results if the track is shaped as a double thread and two catches are arranged diametrically opposite each other on the ink guide.
To achieve a simple construction of the ink guide, the at least one catch may be provided on a bushing which is attached to the rear end of the ink guide. This enables the ink guide to be developed and manufactured according to conventional requirements, while the bushing is connected to the finished ink guide in a separate procedure.
To indicate to the user, during use, that the storage position has been reached, and to be able to interrupt ink guide movement in one direction or the other, the track may have at least one section which has a reduced pitch and defines the storage position. A supporting surface for the at least one catch may be present at the front end of the track, through which the writing pressure occurring during use and acting on the ink guide is absorbed.
The barrel may, in a manner conventional per se, have a front external thread for receiving one cover cap enclosing its front end. Optionally, the cover cap can be attached by simply pushing it on. If a screwable cover cap is provided, a rear external thread can be provided adjacent the rear end area of the positioning sleeve for receiving the cover cap. In this way, the cover cap can be coupled with the rotatable positioning sleeve and the positioning sleeve rotated by rotating the cover cap. That is, in a particularly preferred embodiment of the invention, the closure cap is fastened to the rear end of the positioning sleeve so that the user can grasp the closure cap, and rotate it to thereby rotate the positioning sleeve to move the ink guide into the desired position.
In order [when the cover cap and thus the positioning sleeve are rotated in the direction of movement of the ink guide from the writing position into the storage position] to prevent the cover cap from being detached from the positioning sleeve before the storage position has been reached, the core diameter of the rear external thread and/or the outer diameter of the internal thread of the cover cap can change in the axial direction so that the clamping force established between the positioning sleeve and the cover cap screwed thereon is greater than the force to be exerted on the cover cap to displace the ink guide from the writing position into the storage position. The core diameter of the rear external thread is preferably constant, and the outer diameter of the inner thread of the cover cap changes, resulting in a taper from front to back with a cone opening angle of between about 10.degree. and 16.degree., preferably about 12.degree.. In this case, the front external thread is preferably formed with essentially the same pitch from the rear forward, to avoid an increased clamping force arising in this area.
The clamping force thus established between the rear external thread and the internal thread of the cover cap leads to a coupling of cover cap and positioning sleeve which ensures that the substantially linear movement of the ink guide from the writing position into the storage position can be undertaken by rotating the cover cap and that the cover cap is unscrewed from the positioning sleeve only when the ink guide has reached the storage position. The detached cover cap can then be screwed onto the front external thread in order to protect ink on or in the nib and the ink guide from drying out.
As previously mentioned, the track may have at least one section which has a reduced pitch and defines the storage position in order that, upon movement of the ink guide from the writing position into the storage position, the user can detect that the storage position has been reached and, if the positioning sleeve has a rear external thread for receiving and clamping the cover cap, to generate a resistance to such a further displacement that the cover cap detaches itself from the rear external thread.
If a closure cap is fixed in a pivotal manner to the rear end of the positioning sleeve, the definition or establishment of the storage position by a section with reduced pitch in the track may be dispensed with, and the storage position can be defined by the abutment of the rear end of the ink cartridge against the front surface of the closure cap.
While the cover cap normally separates from the rear external thread if the abutment of the rear end of the ink cartridge against the closure cap causes a certain resistance against further rearward displacement of the ink guide, it cannot be ruled out that the clamping force between cover cap and rear external thread is so great that the user undesirably moves the ink guide (and thus the ink cartridge) further to the rear, despite its abutment against the closure cap, thus opening the closure cap. To avoid this and to achieve a defined storage position, an axially extending support pin may be provided in the base of the cover cap, the pin free end being located directly beside the rear surface of the closure cap when the cover cap is screwed onto the rear external thread, and preventing opening. Opening of the cover cap is prevented as a result of the pressure exerted on the closure cap by the rear end of the ink cartridge. In this way, the support pin blocks opening of the closure cap when the torque exerted on the positioning sleeve leads to a force in the direction of further rearward movement of the ink guide and thus of the ink cartridge. As a result, the closure cap can no longer be opened, rather the torque exerted by the user on the cover cap effects the detachment of the cover cap from the rear external thread.
The provision of the support pin in the base of the cover cap has the further advantage that when the cover cap is screwed onto the front external thread its free end engages, in a manner bracing the ink guide against further forward movement, a supporting surface of the ink guide when the latter is moved in the direction of the writing position so that the tip of the nib is always spaced from all portions of the cover cap. The supporting surface can comprise or consist essentially of the base surface of a blind bore in the ink guide. Thus, if, when the cover cap is screwed onto the front external thread, the user rotates the positioning sleeve, as by gripping the positioning sleeve in the area of the closure cap, he or she is thereby prevented from moving it so far out of the storage position in the direction of the writing position that the tip of the nib comes into contact with the cover cap. This could damage the tip. In particular, the contact between the tip of the nib and the cover cap could result (due to the resulting capillary effect) in ink being released from the ink guide via the tip of the nib into the inside of the cover cap, leading to significant blotting.
It is the primary object of the present invention to provide a fountain pen having an ink guide that can be moved from a storage position into a replacement position that allows simpler replacement of the ink cartridge than is possible in conventional fountain pens. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.